Prunes Processing Plant & Machinery Solutions

Plums are washed and graded by size, and split, bruised and under-ripe fruit is removed. Drying time follows fruit size, so grading is done before the fruit reaches the dryers.

Whole plums, with the stone still in place, are dried in warm air until the flesh is firm and will hold in storage. Prunes are dried before they are pitted, which is the opposite order to apricot and most stone fruit.

Dried prunes are held in bulk and graded by count and size ahead of the finishing line. Bulk holding lets a whole season's crop be finished to order rather than packed at harvest.

Graded fruit is treated with hot water or steam so it takes moisture back and turns pliable. A fully dry prune tears on the pitter, while a conditioned one releases the stone cleanly.

The stone is pushed out of the softened fruit and collected separately, and the pitted fruit is checked for stones left behind. Pit and pit fragments are the defect this stage is judged on, so inspection sits directly after it.

Metal inspection and weight checks run before filling, and the fruit is packed into resealable pouches, trays or cases. Each pack is coded so the lot can be traced back through the finishing line.